If none of the hints in that doc help, there is one more thing you can try.
If a firmware update goes bad enough, it can get the QuNeo stuck where it thinks it is updated, and as such will not be accessible to put it into "boot loader" mode from software.
This is going to be very rare if you are not me (I am working on linux software to update the firmware, and as such flub my firmware pretty often).
However, if it does happen, there is one sure method to get into boot loader mode I like to call "The Wire Trick
- Unplug the QuNeo.
- Plug it in
- Quickly unplug it (before the "rainbow wipe"
- Quickly plug it back in.
You should be rewarded by a solid blue program button. If not, try again.
I have been very successful with this method (>100 times so far), and it does not seem to be extremely timing sensitive other than the unplug has to be after the plug is fully inserted but before the Rainbow Wipe, and plugging back in after that is just as quick as you can physically cycle it out and back in to the jack.